摘要：While the relationship between crop yields and the environmental impacts of crop agriculture has been well‐documented, research on the relationship between farm size and the sustainability of cereal production is limited. Using survey data on 120 farms with both small‐ and large‐scale fields in Northeast China, this paper combines a life cycle assessment and the carbon‐based sustainability index (SI) algorithm to examine how maize productivity and agricultural inputs vary with farm size and to clarify how increasing farm size is correlated with energy use efficiency (EUE) and the SI. The results indicate that maize grain yield did not vary with farm size. Increasing farm size was shown to lead to reductions in the areal (per ha) rates of agro‐chemical inputs, energy depletion, and greenhouse gas emissions and increased in EUE and SI. Fertilizer‐ and fuel‐related agricultural inputs dominated the variations of EUE and SI. A scenario analysis indicates that, if farmers adopt a comprehensive management strategy (i.e., machines appropriate to farm size and recommended fertilizer application rates and crop management strategies), EUE and SI would increase by 68.5% (from 4.45 to 7.50) and 74.3% (from 10.1 to 17.6), respectively. Although increasing farm size could benefit maize sustainable production when matched with technical innovation and machinery coordination, supporting smallholder farmers to increase their resource use efficiency and sustainability is also key in China and other regions where smallholder farms comprise a large portion of the cropland area.
关键词：energy use efficiency;farm size;greenhouse gas emission;life cycle assessment;sustainability index
